Like Ornette, the Rich Halley Trio combines a free orientation with a solid grounding in classic jazz; the blues and bop never seem too far behind anything they are doing. The rhythms and forms are open, but the tones are warm and the moods seldom histrionic. Halley's tenor and soprano saxophones occasionally go off-register for effect, as on "Before Dawn/The Spring" and the title track, but they don't live there. There is a good bit of whimsy here as well, evidenced for example in some of Halley's more childlike lines on "Three Way Shapes." Reed & Storrs play with appropriate omnidirectionality throughout; the bassist laying down a good walking bass and effectively choosing the right spots to wander off-path, while Storrs shows plays with a rhythmic openness and sense of expansiveness in the tradition of the late Ed Blackwell.
Mountain and Plains, then, is most definitely an offering of freely-improvised jazz. But don't let that scare you. The music is open in a way that is more inviting than chaotic. Adventurous for sure, but not necessarily perilous.